<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>card</title>
    <style>
      /* CSS 代码 */
      .card {
        box-shadow: 0 4px 8px 0 rgba(0, 0, 0, 0.2);
        border-radius: 5px;
        width: 300px;
        margin: 20px auto;
      }

      .card-header {
        background-color: #fff;
        border-bottom: 1px solid #ddd;
        padding: 20px;
      }

      .card-body {
        padding: 20px;
      }

      .card-footer {
        background-color: #fff;
        border-top: 1px solid #ddd;
        padding: 20px;
        text-align: right;
      }

      .card-footer .btn {
        margin-left: 10px;
      }
    </style>
</head>
<body>
  <!-- HTML 代码 -->
  <div class="card">
    <div class="card-header">
      <h2 style="text-align: center;">欢迎注册</h2>
    </div>
    <div class="card-body">
      <p>您的验证码是:<h3 style="text-align: center;">@code@</h3></p>
    </h3>
    <div class="card-footer"></div>
  </div>
  </div>
</body>
</html>